Active Ingredient Glossary

Lactic Acid: The Gentle Acid for Beginners

Active Ingredients Glossary · M INCI: Lactic Acid Lactic acid is glycolic acid’s gentler counterpart: It exfoliates more gently, moisturizes at the same time, and is therefore the ideal acid for anyone trying a chemical peel for the first time. If you associate AHAs with red, irritated skin, you’ll discover a much gentler option here. Profile Research Findings Effective against rough, dull skin and feelings of dryness Skin Type: All, including dry and sensitive skin Concentration: 5–10% Routine: In the evening, 1–3 times per week Tolerance Period: Short—mild, but SPF is still required What is lactic acid? Lactic acid is an alpha hydroxy acid originally derived from fermented milk—for cosmetic use, it is now typically produced in a vegan process through the fermentation of sugar. Its molecule is larger than that of glycolic acid. As a result, it penetrates less deeply and works primarily on the skin’s surface: it exfoliates dead skin cells and smooths the skin without affecting deeper layers. One distinctive feature makes it unique among exfoliating acids: Lactic acid occurs naturally in the skin—as a component of the natural moisturizing factor (NMF), which binds water in the stratum corneum. So lactic acid not only exfoliates, it also supports the skin’s moisture balance. Effect: What the Evidence Shows Four out of five bars: The body of research is solid. Its smoothing exfoliating effect, a more even and fresher complexion, and its moisture-retaining properties at moderate concentrations are well documented. Compared to glycolic acid, the effect per application is slightly milder—but the potential for irritation is also significantly lower. For beginners and those with sensitive skin, that’s exactly the point: it’s better to be gentle and consistent than strong and infrequent. Application & Combination Like all AHAs, lactic acid belongs in your evening routine: apply it one to three times a week to cleansed, dry skin, followed by a moisturizer. Beginners should start with about 5% and one application per week. Even though lactic acid is mild, it still makes the skin more sensitive to light: sunscreen during the day is a must. Good Combinations ✓ Hyaluronic acid & polyglutamic acid – enhance the moisturizing effect ✓ Ceramides – help rebuild the skin barrier on days when you’re not using acids ✓ Niacinamide – soothes and refines the skin Note ! Even mild acids increase light sensitivity—be sure to use SPF during the day ! Do not combine with retinol or other exfoliants on the same evening Myth debunked: “Acids dry out the skin”—with lactic acid, the opposite is actually true: at moderate concentrations, it acts as a humectant because it’s part of the skin’s own natural moisturizing factor. Concentration and frequency are key. Lactic Acid in the BONSANA Line SKIN REPUBLIC AHA 15% Exfoliating Serum CHF 3.95 15% · 30 ml SKINCYCLOPEDIA AHA/PHA Exfoliating Serum 20% CHF 8.95 20% · 30 mlFRANK BODY Smoothing AHA Body Lotion CHF 25.00 140 mlMAD HIPPIE AHA Exfoliating Peel CHF 25.90 30 ml Shop Now Gentle acid-based skincare for your routine Cleansing and exfoliating products that won’t overwhelm your skin—fast shipping from our Swiss warehouse. To facial cleansing → Related entries: AHA fruit acids · Glycolic acid · Salicylic acid · Read more: How to use Foot Peel correctly Frequently Asked Questions About Lactic Acid Is lactic acid the right acid for beginners? Yes. Its larger molecule works primarily on the skin’s surface, so it’s less likely to cause irritation than glycolic acid. Starting with a 5% concentration and one application per week is a gentle way to begin. What’s the difference between lactic acid and glycolic acid? The molecule size: Glycolic acid is smaller, penetrates deeper, and is more potent—but it’s also more likely to cause irritation. Lactic acid stays closer to the surface and also helps lock in moisture. Do I need sunscreen when using lactic acid? Yes. Even mild AHAs make the skin temporarily more sensitive to light. During the day, sunscreen with an SPF of 30 or higher is essential during any acid treatment phase. How soon will I see results? You’ll often notice a smoother skin texture after just a few applications. For a visibly more even complexion, you should expect to see results after a few weeks of regular use.